Fig. 4: Adsorption of NPs through the intestinal villi.

a Treatment protocols on the intestinal permeability study of NPs. b CLSM images of NPs absorbed at the small intestinal villi of mice at 2 h post oral administration; blue: nuclei of the intestinal villi stained with DAPI, red: RITC labeled NPs, scale bar: 50 μm. Experiment was repeated three times independently with similar results. c Fluorescence integrated density and d permeation ratio of NPs at the small intestinal villi of mice. Data are presented as the mean ± SD (n = 3 independent experiments). *P < 0.05, *P < 0.01 and ***P < 0.001 by two-tailed Student’s t-test. Source data are provided as a Source Data file. e Competitive adsorption of NPs in the intestinal villi of mice examined by CLSM; blue: nuclei of the intestinal villi stained with DAPI, green: FITC labeled NPs, red: RITC labeled NPs, scale bar: 100 μm. Experiment was repeated three times independently with similar results. f Relative fluorescent intensity of NPs in intestinal competitive adsorption. Source data are provided as a Source Data file. g Treatment protocols on the intestinal uptake study of NPs. h Bio-TEM images of the mucosa of mice at 4 h post oral administration of NPs. Experiment was repeated three times independently with similar results.